Numerous wick-type diffusers are presently available. These diffusers typically comprise a one to sixteen ounce container, such as a glass vase, bottle, or other suitable container filled or partially filled with a fragrance material combined with solvents. A typical diffuser uses a 6-7 ounce container. A wick, such as a natural reed, branch or cotton wick, natural sponge or synthetic polymer foam, protrudes out of the container to allow the fragrance to evaporate into the surrounding air. Solvents used in presently available diffusers typically include, among others, alcohol, or heavy solvents such as petroleum distillates, glycol ethers, phthalate and adipate solvents, ISOPAR hydrocarbon solvents, carbitols, cellosolves, downanols and dipropylene glycol methyl ether.
Currently marketed fragrance diffusers utilize solvents for several reasons. To make the final product appear larger and fuller, these solvent-based diffusers typically include 10%-50% fragrance in containers that may hold 6.5 ounces of liquid. Producers use solvents to fill the remainder of the container with a liquid material that is less costly than pure fragrance materials. These prior diffusers also are made with heavy solvents having evaporation rates less than 0.1 mm Hg to comply with current anti-smog volatile organic chemical (VOC) limitations imposed by law. The manufacturers of these presently available diffusers also claim that solvents are used to control the rate of evaporation of the product. However, presently available diffusers do not evaporate well. They evaporate poorly through the wicking material as the wick becomes saturated with non-evaporative solvents.
The aforementioned, and other, solvents can be dangerous to human health and, since they do not evaporate, hazardous to the environment when emptied into sewage drains and the like. This is particularly significant because millions of pounds of these solvents are disposed of annually. Once the fragrance in these diffusers has evaporated, the hazardous solvents are left behind and normally would have to be disposed of properly and not in a landfill or drain. Hazardous conditions can also result if the container of solvent-fragrance liquid is tipped over and a spill results.
Additionally, existing fragrance diffusers use fragrance mixtures that do not evaporate well through the wicking material. Frequently, to make current products last longer, the users of such diffusers are instructed to flip the reeds by placing the portion of the wicking material that was previously exposed to the atmosphere into the solvent-fragrance mixture, whereby the previously submerged portion of the wick is now exposed to the atmosphere. This procedure is highly detrimental to the performance of the diffuser, and produces a myriad of undesirable results for the user. Flipping the wick material typically results in splashing the fragrance and solvent mixture outside of the container and onto the table or other surface supporting the diffuser.
Also, flipping the wick material typically only continues the odor production of the product for one to seven days, and then the odor level dies down again. This occurs because as the fragrance and solvent system is advancing up the wicking material, and the fragrance is evaporating, the non-volatile solvent becomes concentrated in the exposed portion of the wick. Eventually excessive amounts of heavy solvents remain, with very little fragrance in the wick. After the wick is flipped, the previously submerged portion of the wick is now exposed, but fragrance evaporation continues for only a short period of time.
Further, in present wick-type diffusers, the wick can be easily knocked out of place and damage furniture, carpets, or other surfaces upon contact with the solvent-fragrance mixture. The spilt mixture could also present a human health hazard, as mentioned above.
Due to the flammable and/or combustible nature of most solvent-fragrance mixtures used in present diffusers, with flash points below 155 degrees Fahrenheit, manufacturers must provide a warning label on these products so the user does not place the diffuser near a flame or in a high heat location. Some manufacturers of current diffusers attempt to raise the flash point of their solvent-fragrance mixture by diluting the product with heavy, non-evaporative solvents. This procedure results in a trade off that either potentially damages the environment, or causes the performance of the diffuser to be radically diminished. When the consumer decides that such products have outlived their useful life, there is a tendency to pour the remaining solvent into the drain, causing potential harm to the environment.
An object of the present invention is to overcome all of the above described problems of other diffusers by providing a solvent-free diffuser, or a diffuser comprising only a minor amount of a low volatility solvent, that does not provide potential human health problems or environmental hazards, and yet is attractive, stable and long lasting.
A further object of the present invention is to provide a fragrance diffuser that firmly supports a reed wick, and wherein the fragrance material is specifically formulated to provide optimum fragrance release with the specific reed wick material used in the diffuser.
Another object of the present invention is to allow the fragrance evaporation rate into the adjacent environment to be adjusted by the user without flipping the reed wick. Additionally, the presently disclosed diffuser can be reused, refilled and will continue to function as new.